Weft inserter for travelling-wave shedding looms

ABSTRACT

A weft inserter for travelling-wave shedding looms, said inserter having a body with a leading point, a recess adapted to receive a rotary bobbin, a roller cooperating with a driving roller on a chain conveyor, with a recess for a carrier on said chain conveyor, and a weft outlet brake. A planar base wall of the weft inserter includes an angle not exceeding 45* with a planar front wall thereof, which front wall merges via an arcuate recess into a wall merging in turn into a rear wall of said inserter. The rear wall forms a right angle with said base wall, while in the middle of said rear wall there is provided a notch for said thread outlet brake and a guide for weft thread. The notch extends through said wall towards a slot connecting said arcuate recess with said recess for the rotary bobbin and directed towards the rotational axis of said bobbin rotatably supported on a projection in the bottom of said recess, said weft inserter, when viewed at from said point, being widened by its convex surfaces merging into a top guide face and into a bottom guide face symmetrical with the latter along a middle plane of the inserter, which guide faces are provided, along said base wall, with an upper relieving surface and a lower relieving surface symmetrical with the latter along said middle plane, while in the region where said front wall ceases and merges into said arcuate recess, said front wall is continued as an upper thread separating spring bent in parallel with said base wall, said roller being arranged in the space between said point and said bobbin.

Unite States Patent [191 Zabrodsky et al.

[4 1 Nov. 19, 1974 WEFT INSERTER FOR TRAVELLING-WAVE SHEDDING LOOMS [75] Inventors: Zdenek Zabrodsky; Frantisek Augusta, both of Usti nad Orlici; Zdenek Kramenic, Chocen; Oldrich Chronek, Brno, all of Czechoslovakia [73] Assignee: Vyzkumny ustav bavlnarsky, Usti nad Orlici, Czechoslovakia [22] Filed: June 4, 1973 [21] Appl. No.: 365,998

[30] Foreign Application Priority Data 3,766,950 10/1973 Vasek et a1. 139/12 Primary Examiner-Henry S. Jaudon [57] ABSTRACT A weft inserter for travelling-wave shedding looms,

said inserter having a body with a leading point, a recess adapted to receive a rotary bobbin, a roller cooperating with a driving roller on a chain conveyor, with a recess for a carrier on said chain conveyor, and a weft outlet brake. A planar base wall of the weft inserter includes an angle not exceeding 45 with a planar front wall thereof, which front wall merges, via an arcuate recess into a wall merging in turn into a rear wall of said inserter. The rear wall forms a right angle with said base wall, while in the middle of said rear wall there is provided a notch for said thread outlet brake and a guide for weft thread. The notch extends through said wall towards a slot connecting said arcuate recess with said recess for the rotary bobbin and directed towards the rotational axis of said bobbin rotatably supported on a projection in the bottom of said recess, said weft inserter, when viewed at from said point, being widened by its convex surfaces merging into a top guide face and into a bottom guide face symmetrical with the latter along a middle plane of the inserter, which guide faces are provided, along said base wall, with an upper relieving surface and a lower relieving surface symmetrical with the latter along said middle plane, while in the region where said front wall ceases and merges into said arcuate recess, said front wall is continued as an upper thread separating spring bent in parallel with said base wall, said roller being arranged in the space between said point and said bobbin.

10 Claims, 7 Drawing Figures PATENTEU 1 91974 SHEET 3 3.848.641

FIG.|

WEFT INSERTER FOR TRAVELLING-WAVE SHEDDING LOOMS The present invention relates to a weft inserter for travelling-wave shedding loom wherein weft lengths corresponding to the fabric width are inserted into the warp shed.

The function of the weft inserter is reliably to receive the necessary weft length and uniformly to release it, under a constant tension, during the whole passage thereof through the warp shed. During its passage through the warp shed the weft inserter has to clear its own way therethrough; this process is necessary particularly in the case of the so-called cottered warp ends, or in the case of an incorrect performance of some of the warp shed forming sections. Further, the weft in-' serter should be prevented from laterally deflecting the warp threads, due to a frictional contact therewith, and thus making impossible a reliable and precise intake of the rotary reed discs always into the respective warp end spacings. Finally, the weft inserter has to present the weft thread to the rotary reed in the operating region of the latter so as to cause the reed reliably to receive it, to convey it to the fabric fell, and to beat it up thereonto.

A great many well-known weft inserter constructions are substantially constituted by elongated forwardly pointed bodies provided with a recess housing a rotatably mounted bobbin to receive the necessary weft length. The weft inserters are provided with necessary guide surfaces enabling them to be guided along a stationary reed, and arm furtherprovided with an upper guide face, and means for driving it in the warp shed. One embodiment of weft inserter comprises at its bottom a roller to mesh with a mating roller arranged on a chain conveyor advanced under the warp shed. The weft inserter roller is engaged via a resilient belt below the warp shed with a roller on the chain conveyor which drives the inserter through the shed. On its way outside the warp shed, the weft inserter is carried along by a driving lug projecting from a endless chain conveyor and received in a hole in the weft inserter, said conveyor being designed to transport the weft inserter to a weft supply device in order tobe furnished with a fresh weft length.

In order to obtain a constant tension of the weft thread being released in the warp shed, the weft inserter is equipped, as a rule, with an outlet thread brake formed, for example, of two leaf springs forced resiliently against each other and thus forming a nip zone for the weft as it leaves the inserter.

It is an object of the invention to improve the weft inserter for travelling-wave shedding looms having a rotary reed so as more perfectly to meet the abovedescribed requirement.

In order to eliminate, or at least to mitigate the drawback of the prior art hereinabove referred to, we provide an improved weft inserter for travelling-wave shedding looms, comprising a leading point, a recess adapted to receive a rotary bobbin, a roller cooperating with a driving roller on a chain conveyor and with a recess for a carrier on said chain conveyor, and a weft outlet brake, The weft inserter according tothe invention has a planar base wall which forms an angle not exceeding 45 with a planar front wall thereof. Such front wall merges via an arcuate recess into a wall merging in turn into a rear wall of said inserter; said rear wall is disposed at right angles with respect to said base wall, while in the middle of said rear wall there is provided a notch for said thread outlet brake and a guide for weft thread. The notch extends through said wall towards a slot connecting said arcuate recess with said recess for the rotary bobbin, and directed towards the rotational axis of said bobbin rotatably supported on a projection in the bottom of said recess. Said weft inserter, when viewed from its point, is widened by its convex surfaces merging into a top guide face and into a bottom guide face symmetrical with the latter along a middle plane of the inserter; the guide faces are provided, along said base wall, with an upper relieving surface and a lower relieving surface symmetrical with the latter along said middle plane. Said front wall is continued at the region where said front wall ceases and merges into said arcuate recess, on the one hand, as an upper thread separating spring overlapping said slot and, on the other hand, as a lower thread separating spring bent parallel with said base wall, said roller being arranged in the space between said point and said bobbin.

The inserter carrying roller is of a conical configuration narrowing towards the front wall of the inserter. A recess for receiving a carrying member extends from the lower relieving surface into the projection.

A controlling member for the weft outlet brake is arranged in the notch. The controlling member is constituted by a yoke supported for reciprocation on jaws of said weft outlet brake, the former is provided with an elastic element permitting perfect clamping of said jaw.

In a wall of the recess of the bobbin adjacent the point of the inserter there is provided an additional ar cuate cavity of which the bottom is aligned with the bottom base of said bobbin and forms an acute angle with the slanted lateral cavity wall intersecting a wall of said recess for said bobbin substantially within the level of the top base of the bobbin.

The bobbin is locked by a lid to which a strap plate is fixedly attached relative to said projection, said strap plate having a slot disposed on a line identical with the axes of said opposite slots and the center of rotation of said bobbin.

The recess for the bobbin has a cylindrical shape of which the lateral wall merges, at the side opposite the slot, into two walls disposed at right angles with each other, one of which is parallel with said base wall and the other of which is parallel with said rear wall of the weft inserter.

In order that the invention be better understood and carried into practice some preferred embodiments thereof will be now described with reference to the accompanying, somewhat schematic drawings which, however, are not intended to limit, in any way, the invention scope. In the drawings:

FIG. 1 is a sectional view of a first illustrative embodiment of the weft inserter when it is passing the warp shed;

FIG. 2 is a plan view of the weft inserter of FIG. 1;

FIG. 3 is a longitudinal sectional view of the weft inserter taken along the line A-A in FIG. 2;

FIG. 4 is a rear view of the weft inserter when viewed at in the direction S in FIG. 2;

FIG. 5 is a rear view of a second embodiment of weft inserter in accordance with the invention;

FIG. 6 is a plan view of the weft inserter shown in FIG. and

FIG. 7 is a perspective detail view of the weft outlet brake employed in both embodiments of weft inserter illustrated herein.

Discussing now the drawings in detail, and particularly FIGS. 1 and 2 thereof, it can be seen that the first illustrative embodiment of weft inserter according to the invention has substantially the configuration of a right-angled triangle of which the leading point 2 merges into a front wall 4 corresponding in section to the hypotenuse of said triangle and forming with a base wall 3 an acute angle a not exceeding 45. The rear wall 5, which forms a right angle with the base wall 3, does not meet the front wall 4 at an intersection of these walls 4 and 5. In the region where the walls 4 and 5 meet there is provided in the weft inserter body a substantially arcuate recess 62 comprising the following inner walls; a wall 61 parallel with the front wall 4, and a wall 31 merging, in turn, into a wall 63 formed by bevelling the rear wall 5, walls 31 and 63 being disposed at an obtuse angle a In cross-section the weft inserter is of a wedge-like configuration and is shaped in such manner that the major portion of both its transverse and longitudinal profile occupies, except for an indispensable tolerance, the whole space defined by the warp threads in the shed, the fixed reed 16, and the rotary reed 17. The base wall 3 bears against the fixed reed 16.

Along the base wall 3 a top guide face 8 and a bottom guide face 81 are provided with relieving surfaces 18, 18. From the point 2 comprised within the plane of the base wall 3 and in the axis of symmetry thereof, the weft inserter is widened by convex surfaces 7 merging into said top guide face 8 and said bottom guide face 81, respectively. Said face 8 and 81, are symmetrical along a middle plane 24. (FIG. 4). In the rear or trailing half of the weft inserter said top guide face 8 and said bottom guide face 81 abruptly and symmetrically eonverge towards the rear wall 5, thus forming two relieving surfaces symmetrical along said middle plane 24, i.e., an upper relieving surface 9 and a lower relieving surface 91, the former being provided with a recess 10 receiving a bobbin 11 rotatably supported by a projection 101 provided on the bottom of said recess 10. The peripheral edge of the upper base of the bobbin 11 is bevelled in the form of a conical onrun portion 114. The bobbin 11 is prevented from falling out of the recess 10 by means of a lid 1 secured to the projection 101 by a screw 102.

Above the lid 1 there is provided a strap plate 111 having a slot 112, which plate 111 may be made either integral with the lid 1 or secured thereto in a conventional manner. The portion of the recess 10 adjacent to the point 2 is enlarged in the form of an additional arcuate cavity 103 (FIGS. 2, 3 and 6) of which the bottom is aligned with the bottom base 113 of the bobbin 11. The bottom of said cavity 103 forms with the slanted wall thereof an acute angle a said wall intersecting the wall of the recess 10 substantially at the height of the upper base of the bobbin 11. The cavity 103 is broken by a slot 43 provided in the wall 61. The line connecting the axes of the slot 42 and the slot 112 in the strap plate 111 intersects the axis of rotation of the bobbin 11. The recess 10 has a cylindrical configuration, its cylindrical wall merging, at the side opposite the slot 42, into two planar walls perpendicular to each other, of which one is parallel with the base wall 3 and the other is parallel with the rear wall 5. The corner space defined by said two inner walls is designed to receive the free end of weft thread 33 as it is wound on to the bobbin 11. In the lower relieving surface 91 there is provided a recess 12 for receiving a carrying member 13 constituting a part of a chain conveyor (not shown). The recess 12 is provided centrally in the projection 101. In the bottom guide face 81 there is provided a cavity 82 in the form of a concave spherical cap, which cavity 82 merges, in the direction towards the point 2, into a recess 83 to receive a conical roller 14 narrowing towards the front wall 4 of the inserter, The cavity 82 is designed to receive a roller of the chain conveyor during the passage of the weft inserter through the shed.

In the middle of the rear wall 5 there is provided a notch 19 extending through the bevelled wall 63, the wall 31, the wall 61, and finally merging into the slot 42. In the notch 19 there is arranged a two-jaw outlet brake 20 for the weft thread 33. This brake 20 comprises an upper jaw 201 and a lower jaw 202 which are resiliently forced against each other and are made of two leaf springs spaced at their free ends from each other to provide a reliable onrun for the weft thread 33. The flat springs extend through a slotted controlling member in the form ofa yoke 21 (FIG. 7). For the sake of clarity, the jaws 201 and 202 are illustrated as spaced from each other but in operation, they are permanently forced against each other by said yoke 21. The yoke 21 is embodied either as a gripper, or made of an elastic material, such as, e.g., rubber, or of a dimensionally stable material; in the latter case at least one of the inner walls of said yoke 21 designed to engage the jaws 201 and 202, respectively, is provided with an elastic element, such as, for example, a rubber lining, a helical spring, or the like.

In order to facilitate a displacement of said controlling yoke 21, the notch 19 is slightly widened. Between the wall 31 and the outlet brake 20 the notch 19 is bridged over by a guide of the weft thread 33 in the form of a peg 32 over which the weft thread 33, after having passed the outlet brake 20, is withdrawn from the bobbin 11. In the region where the front wall 4 merges into an arcuate recess 62 (FIG. 2), the front wall 4 in the upper part of the weft inserter is continued as an upper separating spring 43 the length of which is selected so as to overlap the slot 42. Similarly in the lower part of the weft inserter the front wall 4 is continued as a lower separating spring 44 the free extremity of which is bent to lie parallel with the base wall 3. This bending of the lower separating spring 44 permits the rotation of the reed 17. The purpose of the upper separating spring 43, among other, is to prevent the warp threads 15 from penetrating into the slot 42.

The second illustrative embodiment of the weft inserter, shown in FIGS. 5 and 6, includes some minor modifications of the inserter of FIGS. 1-4 incl. The upper relieving furface 9 is pierced by a controlling screw 211 bearing against the upper surface of the lower jaw 202 of the outlet brake 20. The guide peg 32 is here omitted, while the function of the guide for the weft thread 33 is assumed by a recess 321 provided in the stationary upper jaw 201 of the outlet brake 20. The slot 42 is slightly widened in the direction towards the outlet brake 20.

The lid 1 preventing the bobbin 11 from falling out of the recess 10, as well as the strap plate 111, are designed to prevent, during the winding-off process, a premature release of the end of weft thread 33 which is located at the beginning of the spooling process over the center of the bobbin 11.

During the process of filling the weft inserter in the weft supplying device, the leading end of the weft thread 33 is retained by a weft thread clamp (not shown) and is laid over the center of the bobbin 11 into the slot 112 of the strap plate 111. A driving disc (not shown) of the weft supplying unit presses the weft thread against the bobbin 11. As the bobbin 11 begins to turn, the weft thread 33 is introduced between the strap plate 111 and the lid 1. During the weft inserter filling process, the additional arcuate cavity 103 directs a floating free end of the weft thread 33 towards the bottom base 113 of the bobbin 11.

The weft inserter is guided by the fixed reed 16 cooperating with an upper guideway 22 and a lower guideway 23, and is driven from a driving mechanism. The upper guideway 22 forms with the lower guideway 23 an angle corresponding to the shedding angle of the warp threads (FIG. 1). The weft inserter is conveyed through the travelling-wave shed in synchronization with the motion of the rotary reed 17 by means of a mechanism provided in the lower guideway 23 (not shown). This mechanism engages, over the lower plane of warp threads 15, the conical roller 14 of the weft inserter in an oblique upward direction. A component of the force imparted by the mechanism forces the weft inserter by its top guide face 8 against the upper guideway 22 and simultaneously, due to the conicity of the roller 14, by its base wall 3 against the fixed reed 16. Due to friction arising between the adjacent warp threads 15 meeting during the shed exchange, an entanglement of their floating fibers may take place, resulting in a reduction of the wedge-like shed space.

The point 2 of the weft inserter body passing along the central line of the weft inserter path along the fixed reed 16, clears the way for the inserter body in that it penetrates into the space between the warp threads of the reduced or shortened shed angle and, due to the action of the convex surfaces 7, disengages the cottered warp ends from one another.

Thus during the further advance of the inserter, the warp threads 15 are trailed on the guide face 8 and 81 of the inserter until they finally engage the free ends of the upper and lower thread separating springs 43 and 44, respectively. The maximum opening of the shed angle, with all the warp threads 15, successively takes place during the passage of the weft inserter at the extremities of the separating springs 43 and 44. Until now the component of the inserter driving force imparts a friction to the warp threads 15, and, consequently, causes a deflection thereof. This deflection out of the straight course may provoke a so-called overrun in which a warp thread 15 is engaged by an adjacent, i.e., inappropriate disc of the rotaryjreed 17, not in accordance with the desired plan of operation. As soon as the warp threads 15 have left the thread separating springs 43 and 44, the lateral friction provoked by the weft inserter ceases, since the threads reach the region of the relieving surfaces 9 and 91.

The warp threads 15, due to their elasticity, become straightened and assume a position suitable for an accurate onrun between the respective discs of the rotary reed 17. The upper thread separating spring 43 prevents the warp threads from undesirably penetrating into the slot 42 or 42' of the weft inserter. If an incorrect warp crossing takes place, such as, for example, due to an interfering warp thread 15, the upper separating spring 43 can be retracted, as shown in FIG. 2 in dash-lines, whereby the passage of the weft inserter is facilitated, and an excessive overload of the warp threads is prevented. Simultaneously with the abovedescribed operation taking place during the whole period of weft inserter passage through the shed, the weft thread 33 is wound off from the bobbin ll rotating on the projection 101 in the recess 10, and is led over the guiding peg 32 (FIGS. 14) or a recess 321 (FIGS. 5 and 6), respectively, and through the two-jaw outlet brake 20.

Immediately after the weft thread 33 has been in serted into the shed and after the weft inserter has left the shed, the carrying member 13 enters the recess 12 and conveys the inserter towards the weft supplying device and then back towards the shed. During this weft inserter transport step, as shown in FIG. 6, a steel knife (not shown) enters the path of the inserter; such knife, during the passage of the inserter, enters the gap between the jaws 201, 202 of the thread outlet brake 20 and removes dust, fly or yarn remnants which tend to clog the braking space. The knife can be operated only within certain intervals. The braking force of the jaws of outlet brak 20 can be controlled or readjusted by shifting the yoke 21, or by turning the controlling screw 211. The slot 42 or 42 is designed for drawing-in the weft thread 33 between the jaws of brake 20 after the necessary weft length has been wound on to the bobbin 11.

Although the invention is illustrated and described with reference to a plurality of preferred embodiments thereof, it is to be expresaly understood that it is in no way limited to the disclosure of such a plurality of preferred embodiments, but'is capable of numerous modifications within the scope of the appended claims.

What is claimed is:

1. In a weft inserter for travelling-wave shedding looms, having an inserter body with a leading point, a recess adapted to receive a rotary bobbin, a'roller cooperating with a driving roller on a chain conveyor and with a recess for a carrier on said chain conveyor, and a weft outlet brake, the improvement which comprises a planar base wall of the weft inserter including an angle (a) not exceeding 45 with a planar front wall thereof, said front wall merging via an arcuate recess into a wall merging in turn into a rear wall of said inserter, the rear wall forming a right angle with said base wall, in the middle of said rear wall there being provided a notch for said thread outlet brake and a guide for weft thread, said notch extending through said wall towards a slot connecting said arcuate recess with said recess for the rotary bobbin and directed towards the rotational axis of said bobbin rotatably supported on a projection in the bottom of said recess, said weft inserter, when viewed from said point, being widened by its convex surfaces merging into a top guide face and into a bottom guide face symmetrical with the latter along a middle plane of the inserter, said guide faces being provided, along said base wall, with an upper relieving surface and a lower relieving surface symmetrical with the latter along said middle plane, while the region where said front wall ceases and merges into said arcuate recess, said front wall is continued, on the one hand, as an upper thread separating spring overlapping said slot and, on the other hand, as a lower thread separating spring bent to lie parallel with said base wall said roller being arranged in the space between said point and said bobbin.

2. Weft inserter as claimed in claim 1, wherein from said lower relieving surface a recess extends into said projection for receiving a carrying member.

3. Weft inserter as claimed in claim 1, wherein a controlling member of said weft outlet brake is arranged in said notch.

4. Weft inserter as claimed in claim 3, wherein said controlling member is a yoke supported for reciprocation on jaws of said weft outlet brake.

5. Weft inserter as claimed in claim 4, wherein said yoke is a gripper, which resiliently clamps said jaws of said weft outlet brake.

6. Weft inserter as claimed in claim 4, wherein said yoke is provided, at least on one of its inner walls bearing against said jaws of said weft outlet brake, with an elastic element so as to resiliently clamp said jaws of said weft outlet brake.

7. Weft inserter as claimed in claim 1, wherein said roller is of a conical configuration narrowing towards said front wall of the inserter.

8. Weft inserter as claimed in claim 1, wherein a wall of said recess for said bobbin adjacent said point there is provided an additional arcuate cavity of which the bottom is aligned with the bottom base of said bobbin and includes an acute angle with the slanted lateral cavity wall intersecting a wall of said recess for said bobbin substantially within the level of the top base of said bobbin.

9. Weft inserter as claimed in claim 1, wherein said bobbin is locked by a lid to which a strap plate is fixedly attached relative to said projection, said strap plate having a slot, said slot in said wall, and the center of rotation of said bobbin.

10. Weft inserter as claimed in claim 1, wherein said recess for said bobbin has a cylindrical shape of which the lateral wall merges, at the side opposite the slot into two walls forming right angles with each other, one of which is parallel with said base wall and the other of which is parallel with said rear wall. 

1. In a weft inserter for travelling-wave shedding looms, having an inserter body with a leading point, a recess adapted to receive a rotary bobbin, a roller co-operating with a driving roller on a chain conveyor and with a recess for a carrier on said chain conveyor, and a weft outlet brake, the improvement which comprises a planar base wall of the weft inserter including an angle ( Alpha ) not exceeding 45* with a planar front wall thereof, said front wall merging via an arcuate recess into a wall merging in turn into a rear wall of said inserter, the rear wall forming a right angle with said base wall, in the middle of said rear wall there being provided a notch for said thread outlet brake and a guide for weft thread, said notch extending through said wall towards a slot connecting said arcuate recess with said recess for the rotary bobbin and directed towards the rotational axis of said bobbin rotatably supported on a projection in the bottom of said recess, said weft inserter, when viewed from said point, being widened by its convex surfaces merging into a top guide face and into a bottom guide face symmetrical with the latter along a middle plane of the inserter, said guide faces being provided, along said base wall, with an upper relieving surface and a lower relieving surface symmetrical with the latter along said middle plane, while the region where said front wall ceases and merges into said arcuate recess, said front wall is continued, on the one hand, as an upper thread separating spring overlapping said slot and, on the other hand, as a lower thread separating spring bent to lie parallel with said base wall said roller being arranged in the space between said point and said bobbin.
 2. Weft inserter as claimed in claim 1, wherein from said lower relieving surface a recess extends into said projection for receiving a carrying member.
 3. Weft inserter as claimed in claim 1, wherein a controlling member of said weft outlet brake is arranged in said notch.
 4. Weft inserter as claimed in claim 3, wherein said controlling member is a yoke supported for reciprocation on jaws of said weft outlet brake.
 5. Weft inserter as claimed in claim 4, wherein said yoke is a gripper, which resiliently clamps said jaws of said weft outlet brake.
 6. Weft inserter as claimed in claim 4, wherein said yoke is provided, at least on one of its inner walls bearing against said jaws oF said weft outlet brake, with an elastic element so as to resiliently clamp said jaws of said weft outlet brake.
 7. Weft inserter as claimed in claim 1, wherein said roller is of a conical configuration narrowing towards said front wall of the inserter.
 8. Weft inserter as claimed in claim 1, wherein a wall of said recess for said bobbin adjacent said point there is provided an additional arcuate cavity of which the bottom is aligned with the bottom base of said bobbin and includes an acute angle with the slanted lateral cavity wall intersecting a wall of said recess for said bobbin substantially within the level of the top base of said bobbin.
 9. Weft inserter as claimed in claim 1, wherein said bobbin is locked by a lid to which a strap plate is fixedly attached relative to said projection, said strap plate having a slot, said slot in said wall, and the center of rotation of said bobbin.
 10. Weft inserter as claimed in claim 1, wherein said recess for said bobbin has a cylindrical shape of which the lateral wall merges, at the side opposite the slot into two walls forming right angles with each other, one of which is parallel with said base wall and the other of which is parallel with said rear wall. 